Supervisory control system



March 4, 1930. WENSLEY 1,749,553

SUPERVISORY CONTROL SYSTEM Filed Aug. 6, 1923 9 Sheets-Sheet l TNESSE INVENTOR %L 4 Ra J. (M ns/0y ATTORNEY March 4, 1930. R. J. WENSLEY SUPERVISOR! CONTRQL SYSTEM Filed Axig. 6, 1923 9 Sheets-Sheet 2 a SQN o o Q2 5 Y Rm w 3 a ma n V A W WITNESSES: gw bflwd March 4, 1930. R. J. WENSLEY SUPERVISORY CONTROL SYSTEM File'd Aug. 6, 1923 9 Sheets-Sheet 3 w QR wfw w a 9mm m 8 M w w m w m WW w J M m y w w m Q QNMIJ "II I W T "I Wh Tum www \ww 5w vvw QM wxw vmw March 4, 1930. J, w s 1,749,553

SUPERVISORY CONTROL SYSTEM ATTORNEY Ma lh 4, 1930. J WENSLEI'YI 1,749,553

SUPERVI SORY CONTROL: SYSTEM INVENTOR WITNESS W 4 Pay (1 (Wm/ 1x ATTORNEY March 4, 1930. R. J. (ENSLEY SUPERVISORY CONTROL SYSTEM Filed Aug. '6, 1923 9 Sheets-Sheet 6 INVENTOR 7 Roy J WPflJ/fy BY ATTORNEY Marh 4, 1930. J, w Y ,749,553

SUPERVISORY CONTROL SYSTEM Filed Aug. 6, 1925 9 Sheets-Sheet 7 INVENTOR Raye! Wars/W ATTORNEY March 4, 1930. R. J. WENSLEY SUPERVISORY CONTROL SYSTEM 9 Sheets-Sheet 8 Filed Aug. 6, 1923 INVENTOR Po J Wms/gy ATTORNEY ZZZ' ZZZ March 4, 1930. R. q. WENSL'E-Y 4 5 SUPERVISORY CONTROL SYSTEM INVENTOR fiq J WP/as/fy BY A+TORNEY I Patented Mar. 4,

- a two-wire trunk line connecting the dis- UNITED sTA'rss PATENT ornca not .1. waiver, or monwoon. rmsnvnm, assrauon 'ro wnsrmonousn swarm-c a IANUIAO'I'UBING comm, A conroaa'rrou or rmsnvun BUPERVISORY CONTROL BYS'I'EI Application filed August a, 192:. mm Io. 0mm.

at a central point or control ofiice or station may supervise and control all power or apparatus units in the substations of a complex electrical distributing system. These substations may be of the manual or automatic t pe.

In the present instance, I have shown my invention applied to an electrical system of distribution having automatic substations, though it is by no means limited to this use. In accordance with my invention, I have provided a roup of supervisory lamps and controlling eys for each substation to be used for supervising and controlling the operation of power units therein. There is patch ers ofiice to each substation. Associated with each end of each trunk line is a directively controlled automatic switch. Also, in each substation, thereis an automatic sending equipment associated with the trunk line.

In the dispatchers. ofiice, an automatic impulse sending device is provided which is controlled by the operation of said keys.

In brief, the operation proceeds as follows: When one of the apparatus units at a substation changes its condition, under automatic control, the automatic impulse sender in the substation operates to send series of impulses over the trunk line in accordance with the apparatus unit operated. Responsive to these operations, the automatlc directively controlled switch, associated with the trunk line in the dispatchers oilice, is operated to control the operation of the supervisory signals. The operation of these signals serves to apprise thedispatcher of the operation of the apparatus unit. In order to operate an apparatus unit in any substat1on,

the dispatcher operates a ke corres ondi to the elperation of the apgaratus l init dia sired. h1s operation causes the trunk line leading to the desired substation to be assocrate'd with the automatic impulse sending device in the dispatchers ofiice. The device then automatically functions to send a code of lmpulses over the trunk line to operate the dlrectlvely controlled switch in the selected substation. As a result of the operation of the switch, the proper a paratus unit is controlled, as desired, by the dispatcher.

One of the features of my invention resides 1n the provision of an automatic'sender in the d spatchers ofiice which functions to repeat 1ts sendmg operation indefinitely until proper operation of the desired apparatus unit is secured at the substation.

Another feature of the invention resides in the provision of special load-indicating arangements whereby the dis atcher is apprised of the load on each substation. Still another feature of my invention is the provision of means for operating an automatic switch at each end of a two-conductor trunk line simultaneously.

There are other features of y invention, which, together with those set orth, will be described hereinafter with reference to the accompanying" drawings.

Referring now to the drawings, comprising Figures 1 to, 9, inclusivejI have shown by means of conventional diagrams suflicient of..the circuits and apparatus to enable my invention to. be readlly explained and understood. I

Figures Lto 7 inclusive, when placed side by side with the corresponding lines at the ends thereof in alinement, illustrate the circuits of my complete system. Figs. 1, 6 and 7 are diagrammatic views of the equipment located in the load dispatchers ofiice, while Figs. 2, 3, 4 and 5 are similar views of the selective and controlling equipment in an automatic substation.

Figs. 8, 9, 10 and 11 are similar views of modifications of my invention.

Referring now more specifically to Fi- 1, in the u per left-hand corner thereof is shown a ey K. This key is one of several rou file-t II'OW type. A switch F is a find er switch of the usual rotary type, the wipers of which move in a forward direction only. The finder switch is provided with four wipers 123 to 126, inclusive, each of which is adapted to engage a contact bank comprisin twenty-five contact members. The wipers-o the switch have no normal position. The switch CD is a code sending switch similar in mechanical construction to the finder switch F. The mechanical construction of the finder switch F is similar to that shown in Clement Patent No. 1,107,153, with the exception that the wipers of the switches in the present case are advanced upon the deenergization of the stepping magnet instead of upon the energization, as is shown by Clement. On account of differences in circuit design, the switch CD is rotated to normal position at the end of each operation.

In Fig. 2, there is shown a connecter switch H. This switch is of the same mechanical construction as the finder switch F. However, its circuits have been so designed as to enable it to be directively controlled. 1

Fig. 3 shows two groups RG1 and RG of selecting relays, the relay group RG-.1 being the tens selecting group and the relay group RG being the units selecting group.

The relays 401 to 404, inclusive, in Fig. 4,

are those selected by the operation of the selective relays of Fig. 3. The contactor 445 may be any one of the contactors in the substation. The relays 420 to 422, inclusive, are provided for the purpose of controlling the operation of the finder switch F-1 of Fig. 5,

in accordance with the position of the contactor 445. An ammeter A of the well known Kelvin balance type is connected to an ammeter shunt of the direct-current supply busses 440 and 441 and operates to shift the contact maker 433 in accordance with the voltage across the busses.

In Fig. 5 is shown a finder switch F1 and moods sending switch CD-1. These switches are very similar to the switches F and CD previously described.

In Fig. 6 is shown a connector SW1t0hH1 similar to the connector switch H described above.

The relay groups RG-4 and RG-5, shown in Fig. 7, are selective relays similar to those shown at RG and RG-l, Fig. 3. The relays 700 to 703,.inclusive, control the operation of the supervisory lamps L. The relay group RG3 comprises relays for controlling the load indicating lamps L1.

In Figs. 8 and 9, I have illustrated a modification of my invention showing alternative arrangements for connecting the control keys in the dispatchers oflice.

Fig. 10 shows the means employed for sis of keys and is of the ordinary dou-- multaneously sending impulses in both directions over a two-conductor trunkline.

Fi .11 shows an arrangementfor increasing t e number of keys that may be selected by using a pluralit of finder switches.

Having briefly escribed the apparatus shown in the drawings, I'will now escribe .jits detailed circuit operation. In order to .do this, it may be assumed that the contactor 445 closes. The closing of the contactor 445 may occur in response to certain conditions brought aboutby the operation of the ordinary automatic controlling equipment of the substation. This equipment has not been shown in the drawings, as it is well known.

When the contactor 445 operates, a circuit is closed which may be traced from ground by way of the spring 446, and through the winding of the relay 422 to battery. The relay 422 is energized by this circuit and, upon operating, its armature 429 closes a cir cuit for the relay 421. The relay 421 is energized and attracts its armatures. Prior to this time, the relay 420 has been energized as a result of the relay 422 being ino erative. When the relay 422 was energized, t e relay 420 did not retract its armatures, because of the fact that it had established a looking or holding circuit for itself at armature 423.

When the relay 421 is energized, it operates to establish a locking circuit for itself at armature 426 and to close a circuit which may be traced from ground by way of the armature 427 and its front contact, the front contact and the armature 424, the common conductor 462, the front contact and the armature 510, through the winding of the stepping magnet 504, and thence to the battery by Way of the back contact member and the armature 540 of the relay 528. The stepping magnet 504 is immediately energized to place its pawl associated bank contact 518, the conductor 463, the armature 425 and its front contact, the front contact and the armature 428, the common conductor 464, and through the winding ofthe relay 528 to the battery. The

relay 528 is immediately operated over this circuit. 1

As a result of the energization of the relay 528, the circuit of the stepping magnet 504'is opened at armature 540 and, at armature 541,

a circuit is completed which extends from ground by way of the said armature and its front contact, through the winding of'the slow-release relay 533, and thence to the batdeenergization.

tery by way of the back contact and the armature 552. Another result of the ener 'za-' tion of the rela 528 is that a circuit is c osed through grount by way of the wiper 555 and its associated back contact, the armature 509 and its back contact, the armature 542 and its front contact, and through .the winding of the relay 527 to the battery. Another circuit in parallel with that described above, except that it goes by way of the armature 544 and its back contact and the armature 543 and its front contact, ma be traced for energizing the relay 525. The relay 527, uponoperating, at its armature 539 closes a circuit for the relay 526.

At this point, it may be Well to mention the peculiar construction of the armature 539 of the relay 527. The armature 539 is weighted and is so constructed that, when the relay 527 is deenergized, the armature 539 vibrates for some time on account of its momentum. The adjustment between the front and back contacts is so made that the armature 539, in decreasing the amplitude of its operation, first permanently opens the circuit of the relay 525. The operation of the relay 525 is without particular function at the present time. The relay 526, upon operating, at its armature 538 closes a circuit for the relay 530 and at its armature 537 establishes a circuit which extends from ground by way of the armature 541 and its front contact, through the wind ing of the repeating relay 501, the armature 537 and its front contact, and thence to bat tery, by way-of the back contact and the armature 552 on the stepping magnet 534 of the code sending switch CD1.

The relay 530 is energized from the previously traced circuit and, upon operating, it closes a circuit at armature 546,which extends from the battery, by way of the front contact and the armature 546, through the winding of the slow-release relay 532,'and' thence to ground, by way of the back contact and the armature 507. The relay 532, upon operating, at armature 550 closes a circuit for the slow-release relay 531. By the operation of the relay 531, a circuit is completed which extends from ground by way of the armature 506 and its back contact, the front contact and the armature 549, the front contact and the armature 551, through the winding of the magnet 534, the wiper 557 and its associated bank contact, and thence to battery, by way of the armature 546 and its front contact. The magnet 534 is energized over this circuit and operates to place its pawl in such position as to operate the switch shaft upon its Another result of the energization of the magnet 534 is that the circuit of the slow-release relay 533 is opened at 552 as is, also, the circuit of the repeating relay 501.

When the circuit of the relay 501 is closed, as previously described, this relay operates.

As a result of this operation, a circuit is closed over the trunk conductors 590 and 591 for the line relay 607 of the connector switch I at the armature 616, and at the armature 614,

closes a circuit for the slow-release relay 601 from ground through battery, front contact and armature 614. winding of relay 601, and

front contact and armature 617 to ground. The cnergization of the relay 601 merely prepares certain circuits which function later. The energization of'the magnet 623 placesp'ts pawl in position to operate the switch shaft upon the deenergization of the magnet.

Now when the circuit of the repeating relay 501 in the code sending switch CD--1 is opened by the energization of the magnet 534, previously described, this relay is deenergized to open the circuit of the line relay 607 of the connector H1. The deenergization of the line relay 607 opens the circuit of the slowrelease relay 605 and also the circuit of the magnet 623. The retraction of the armature of the magnet 623 causes its associated pawl to advance the switch shaft carrying the switch wipers 630 to 633, inclusive, into engagement with the first set of bank contacts. The operation of the connector H1 from its normal position'closes a circuit for the relay 606 from ground through the winding of relay 606, the switch wiper 632 and battery to ground. The relay 606, upon operating, places ground upon the conductor 650 at the armature 619, and, at the armature 621, closes a circuit for the relay 770. The relay 770, upon attractin its armatures, closes a locking circuit for itself at the armature 771 and at the armature 772 closes a circuit for an audible alarm (not shown) and the alarm lamp 773. The attention of the load dispatcher is thus drawn to the fact that an operation has been performed at the substation.

Referring now to the code sending switch CD1, it will be remembered that the energization of the stepping magnet 534 also opened the circuit of the slow-release relay 533. After a short interval, this relay deenergizes and opens the circuit of the stepping magnet 534 at armature 551. The magnet 534 immediately deenergizes to advance the wipers 555 to 558, inclusive, into engagement with the first set of bank contacts and, at armature 552, closes the circuit of the repeating relay 501 and also the circuit of the relay 533. The relay 533 energizes to close the circuit of the stepping magnet 534 and the repeating relay 501 energizes to close the circuit of the line relay 607 to the connector -H. 1.

The relay 502 is energized over this circuit and operates at armature 506 to open the circuit of the stepping ma et 534 and to prepare another circuit at t e front contact of this armature for the said magnet. An additional result of the operation of the relay 502 is that the circuit of the slow-release relay 532 is opened at armature 507. After a short interval of time, the relay 532 is deenergized to open the circuit of the slow-release relay.

531. Upon the retraction of the armature 549 of the relay 531, a circuit is completed which extends from ground by way of the armature 506 and its front contact, the bagk contact and the armature 549, the front contact and the armature 551, through the winding of the steppingmagnet 534, the wiper 557 and its associated bank contact, and thence to the battery, by way of the armature 546 and its front contact.

The magnet 534 is energized over this circuit and actuates its armatures, to its associated pawl, to open the circu1t of the slow-release relay 533, and also to open the circuit of the repeating relay 501. The slowreleasev relay 533 is deenergized, after .aninterval, to open the circuit of the stepping magnet 534, which is deenergized,'to again close the circuit of the slow-release relay 533 and to open the circuit of the repeating relay 501. The alternate operation of the relay 533 and the magnet 534 again occurs'until the wipers 555 to 558, inclusive, are advanced into engagement with the bank contact set which includes the bank contact 563. i

' During the operation of the code sending switch CD1, while its wipers were rotated in search of the contact set which includes the bank contact 561, the circuit of the relay 501 was intermittently opened and, consequently, the circuit of the line relay 607 of the con- I nector H1.- It is true that the circuit of the slow-release relay 533 indirectly controls the speed of the o eration ofthe repeating the end of the position I occur were" the relay 605 to be deenergized between deenergizations of the" relay 533 -in the switch CD-l, the vtime constant of the I slow-release relay 533 is materiall faster than the time constant of the slow-re ease relay 605. i

Each time'the circuit of the line relay 607 i is opened, this relay is deen'er'gized to open the circuit of the slow-release relay 605 and also the circuit of the ste ping magnet 623. The ma at 623 is thus deenergiud a plurality 0 times to advance the wipers 630 to.

633, inclusive into engagement-with the bank contact set which corre onds to the number of impulses sent over t e trunk line, as determined by (the number of steps that the code-sending switch CD has taken to find the bank contact set including the contact 561. It will be assumed that this bank contact set selected by the connector H-l includes the contact 640.

As the wipers of the connector H-1 have been rotated pastthe normal set of bank contacts, the orlginal energizing circuit of the slow-release relay 604 is opened. However, the relay 604 is not deenergized until the termination of the first series of impulses. This result is due to the factthat, at each retraction of the armature of the line relay .607, a circuit is closed for the rela 604.

By the deener 'zation o rst series of impu s, the circuit of the slow-release relay 601 is opened at the armature 614, and a circuit is closed at the armature 616 which extends from the battery, by way of the conductor 662, through the winding of the relay 708, the conductor 651, the bank contact 640, the wiper 630, the front contact and the armature 608, and the front contact and the armature 617 to ground. The relay 708 is energized over this circuit and operates to open the locking circuits of the certain relays in the group"RG5 at the armature 725, to close its locking circuit at the front contact of the armature 725 to ground on the conductor 650, which has been grounded previously by the operation of the relay 606. Other results of the energization of the relay 7 08 are that at the armature 726, aselectin circuit is prepared and, at the armature 28, a circuitis closed extending from ground by way of the armature 609 and its front contact, the conductor 659, the armature 728 and its front contact, and through the winding of the relay 738 to the battery. The relay 738 is energized over this circuit and controls certain circuits that will be described later. 7

Returning now to the operation of the code sendingswitch CD-1, when the wipers 555 to 558, inclusive, are brought into engage ment with the bank contact set which includes the contact 563, as previously described, a circuit is" completed which extends from ground by way of the armature 427 and the rela 604 at its front contact, the front contact and the armature 424, the com'mon conductor 462, the wiper 512, the bank contact 516, the conductor 461, the armature 430 and its front contact, the conductor 466, the bank contact 563, the wiper 556, and through the winding of the relay 502 to battery.

The relay 502 is energized over the above circuit and operates, as before, to open the circuit of the stepping magnet 534 at the armature 506 and to open the circuit of the slow-release relay 532 at armature 507. The slow-release relay 532 is deenergized to open the circuit of the slow-release relay 531, which also retracts its armature. As a result of the latter operation, the stepping magnet 534 is operated to open the circuit of the interrupter relay 533, which retracts its armature to open the circuit of the stepping magnet 534. The magnet 534 is thus deenergized'to advance the switch wipers 555 to 558, inclusive, into engagement with the next set of bank contacts.

As a result of this operation, the circuit of the relay 502 is opened and this relay retracts its armatures. The 'deenergization of the relay 502 opens the circuit of. the stepping magnet 534 and closes a circuit for the slow-release relay 532.. The relay 532 is energized and operates to establish a circuit for the relay 531. The latter relay, upon being energized, reestablishes the circuit of the stepping magnet 534. The stepping magnet 534 now intermittently operates to advance the wipers 555 to 558, inclusive, until they are brought into engagement with the twenty-fifth set of bank contacts.

During the second advancement of the wipers of the code sending switch, each time the stepping magnet 534 operates, the circuit of the repeating relay 501 is opened and this relay retracts its armature to produce a corresponding number of interruptions in the circuit of the line relay 607 of the connector H-1. Upon each retraction of the armature 620 of the relay 607, the circuit of the stepping magnet 623 is opened and the magnet operates toadvance the wipers 630 to 633, inclusive, into engagement with the bank contact set which corresponds to the number of impulses sent'over the trunk line, as determined by the second movement of the wipers of the code sending switch CD1. It will be assumed that this contact set includes the bank contact 641.

- When the wipers of the connector H-1 are brought into this position, no more impulses are sent over the trunk line until the slow-release relays 533 and 532 of the code sending switch CD1 are deenergized. During the advancement of the switch wipers to their second position, when the wiper 631 engages the twelfth, thirteenth and fourteenth'set of bank contacts, a circuit is completed for the relay 603. The relay 603, upon being energized,

closes a circuit for the slow-release relay 601 at the armature 611, at the armature 612 prepares a circuit for maintaining itself energized, and at the armature 613 removes battery from the conductor 661. As a result of this operation, the slow-release relay'603 in the connector H1, which has been maintained energized by the operation of the armature 620 of the line relay 607, retracts its .armatures, thereby opening the circuits of the slow-release relay 601 at the armature 611 and, at the armature 613 completes a circuit which extends from the battery by way of said armature and its back contact, the conductor 661, through the winding pf the relay 705, the conductor 657, the bank contact 641, the wiper 630, the front contact and the armature 608 to ground by way of the front contact and the armature 617 The relay 705 is energized over this circuit and operates to establish a locking circuit for itself at the armature 719, and to prepare a circuit at the nggnature 720 for short-circuiting the relay As previously described, the code sending switch CD1 is stepped around to its twenty-fifth position after the termination of the second series of impulses. The wipers of the connector switch H-1 are also stepped in synchronism with the wipers of the code sendmg switch CD-l and are brou ht to rest in inggagement with their twenty-fi th set of conac s.

In the'code sending switch CD1, the operation of the wipers 555 to 558, inclusive, to their twenty-fifth set of bank contacts opens the circuit of the relay 527 at wiper 555 and also the'energizing circuit of the slow-release relay 525. The relay 527 immediately retracts its armature. By reason of the peculiar construction of the armature 539, previously described, this armature vibrates for an interval of time, thus alternately closing thecircuits of the slow-release relays 526 and 525. For the reason explained previously, the relay 525 is the first to retract its armature. The de-energization of the relay 525 prepares a circuit for the relay 503.

Another result of the switch wipers of the code sending switch CD1 being brought into engagement with the twenty-fifth set of bank contacts is that a circuit is com leted extending from ground by way of t e wiper 555, the bank cont-act 560, and through the winding of the relay 529 to battery. The relay 529 operates to open another point in the energizing circuit of the relay 525 which it controls at the armature 544 and to close the circuit of the relay 503. Upon being energized, the relay 503 operates to establish another circuit for the relay 528 at the armature 508 and to close a circuit at the armature 507 which extends from ground by way of the said armature and its front contact, the wiper 511, the bank contact 515, the conduc- I tor 460, and through the winding of the resistor 431 to battery. This circuit serves to I short-circuit the relays 420 and 421. Conseuently, these relays retract their armatures. he relay 420, upon retracting its armatures,

opens its locking circuit at armature 423, also 7 removes ground from the common conductor 462 at the armature'424,- and at the armature 425 removes one ground connection from the conductor 464. The deenergization of the re 1 ing relay 501 is retained energized for an interval after the wipers of the code, sending switch CD1 engage the twenty-fifth set of bank contacts. Upon retracting its armature, the relay 602 closes a circuitwhich extends "from ground by way of the back contact and the armature 610, the conductor 660, the armature 726 and its front 'contact-, the front contact and the armature 720, and through the winding ofthe resistor 712 to battery. This circuit serves to shunt out the relay 700 which retracts its armature. The latter operation opens the circuit of the supervisorylamp 715 and closes a circuit for the super-.

visory lamp 717. By reason of these changes in supervlsory signals, the dispatcher is apprised of the change in position of the contactor 445 in the substation.

Returning now to the operation of the code sending switch GD1, the slow-release re lay 526 is finally deenergized and itopens the circuit of the repeating relay 501 at the armature 537 and, at the armature 538, it opens the circuit of the relay 530. The deenergization of the relay 530 opens the circuit of theslow-release relay 532 at the armature 546 and, at the armatures 547 and 548, completes a circuit which extends from ground by way of the armature 548 and its ack contact, through the winding of the stepping magnet 534, the armature 547 and its back. contact, the twenty-fifth bank contact, with which the wiper 558 is in engage- -ment, and the said wiper, and thence to the battery by way of the back contact and the armature 552. The stepping magnet 534 is energized over this circuit and operates to restore the wipers 555 to 558, inclusive, to their normal positions, whereupon the circuit of the magnet 534 is opened and its operation ceases.

As a result of the wipers of the code send-v ing switch being brought to their normal position, the circuit of the relay 529 is opened and this relay retracts its armatures to open the circuit of the relay 503. The slow-release relay 532, upon retracting its armature, opens the circuit of the 'slow-actin relay 531 which is also deenergized; The re ay 503, upon retracting its armatures, opens the circuit of -opens the circuit of relay 770 which is alread the relay 528 at the arniature 508 and, at the armature 507 removes the shunt from the circuit of the relay 421. It will be remem-.

bered that the relay 422 is now in an operated position and,vconsequentl the relay 421 is ener ized to establish a -ocking circuit for ert. The deenergization of the relay 528 in the code sending switch CD1 merely restores certain circuits to their normal condition. The deenergization, of the relay 501, which occurred immediatel after the deenergization of the slow-re ease relay 526, the linerelay 607 of the connector H1. 4

As the circuit ofthe relay 607 is opened,

this relay is deenergized to open the circuit of the slow-release relay 605. Upon retractin its armatures, the relay 605 closes a circu1t .for the stepping magnet 623 which extends from battery b way of the wiper 632 of the twenty-fifth contact and the armature 624, the back contact and the armature 618, and through the winding of the stepping magnet 623 to ank contact, the back ground. The stepping magnet 623 o crates f to restore the wipers 630 to 633 to their normal position.

As the switch wiper 632 moves from its 25th to its first contact, the energizing circuit for the relay 606 is opened. The relay 606 is deenergized and removes ground from the conductors 649 and 650 at'armatures 611 and .621, respectively. Removal of ground from the conductor 649 has no eflfect on the armature 771 and can 0 y be released by opening the key K1. Removal of ground from the conductor 650 opens the locking circuit of the relay 705 and this relay, as a result, deenergizes.

In the above described manner, the apparatus is released following the sending of the supervisory signal to the dispatcher, notifying him of the automatic operation occurring in the substation.

It will be noted that the supenwisory sig nal 717 is not actuate-d immediately after the two series of impulses which caused its ,selection. It is operated when the wipers of the connector H-1 are brought into their twenoperation of the supervisory slgnals is prevented, because, should either the switch CD locked up over i in the substation or the connector H-1 in the dispatchers ofiice get. out of synchronism with the other, the. wipers of each of the switches will not be in their twenty-fifth position simultaneously.

As willbe clear from the operations derelay 602 over the first twenty-four contacts of wiper 633 and the armature 617 of the re-"' lay 605. The relay 605 being slow to operate,

' is normallymaintained energized durm the periods while the si nallingline 591 an 592 19 is open and relay 60 is dee i'er ized. During the first and second pause,j'w%ile the relays 607 and 605 are energized, relay '602 remains energized. When, however, the switch CD-1 reaches its 25th contact'andthethiid pause occurs, if the wipers 630. to 6330i switch H-1 are in synchronism with; the wipers of switch CD-1' at the remote station, and are therefore on their 25th contact, the energizing circuit for the relay-602 is opened at the wiper 633 in engagement with its 25th contact. This pause issl'lfiiciently long to deenergize relay .602. Upon deenergization of the relay 6Q2fthe armature 610 engages its back contat and p the" operating circuit is completed. This is the normal operation. 1

In the event, .h owever, that the switches H1 lag behind the 'switches CD-1, when the switch (SD-1 reachesits 25th contact, a pause will occur as described above. The switch 633 will not at this-time be in engagement with its 25th contact but with some preceding contact, so that the circuit for relay 602 is not opened 'at this time and the relay 602 remains energized thus maintaining the supervisory circuit open. At the completion of the pause period,-the switch CD1 is restored to normal, thereby deenergizing the relay 607. 'The relafi' 605 will, thereupon, be deenergized and wi in turn, open the energizing circuit for the-relay 602 at the armature 617. The relay 602, however, being slow to deenergiz'e, holds its armature up for some interval of time thereafter. In the meanwhile, however, an energizing circuit is completed for the stepping magnet 623 over' the armatures 618 and 624 and the wiper 632 tofbattery and ground,--completing a vibrating circuit which steps the wipers v630 to 633 from contact to contact untll they are 'restored to their normal position. As soon as all of the switches are restored to normal, the

circuit for relay 606is opened at the first contact of the wiper 632 and this relay is deenergized to open the locking circuit of the selecting relays in the groups RG-4 and RG-.5 at the armature 619 without completing the supervisory circuit.

On the other hand, in the event that the switch H-1 is ahead of the switch CD1,

when H-1 reaches its 25th contact there will not be a pause of suflicient duration to deenergizes relay 602 as described above and on the next step of the switch H-1, the looking circuits for the selecting relays in the roups RG--4 and RG5 will be opened. he pause then occurring will not close the prepared supervisory circuit. The dispatcher, hearing the buzzer but noting that no chan'g'e'in .sigua l lamps has occurred, will,

thereu on, transmit a checking code describe hereinafter.

In the event. of an operation by the disatcher' wherein the supervisory operation .15 not completed for reasons described above, the operating code will .be repeated and the relays 420 or 421 will be ,reenergized to repeat the code as described hereinafter.

From the descriptionthus far it will be noted that the contact'518 on the bank of finder switchesis individual to the contactor 445. f Similarly, each of, the other 24 contacts on the bank of switches 514 is individual to a circuit breaker. The first pause "in the code transmitted'is determined directly by the position at which the finder switches I stop, as will be noted by the connection between the contacts 561 and 517. It will be further noted that the second pause in the code is dependent upon whether the circuit breakcr'ofcontactor 445 is open or closed which, in turn, results in either an energized or? a deenergized condition of relay 422.

With the relay 422 deenergized, the armature 430 closes its back contact and a circuit is completed over the conductor 465, which is connected to contact 562. With the relay 422 energized as a result of the circuit breaker being closed, the armature 430 closes a circuit over its front contact which is completed over the conductor 436, contactor 563. For

each of the twenty-five circuit breakers, it will be noted, therefore, that there are two difierent codes differing from each other by the number of impulses in the second group which, in turn, is directly dependent upon the position of the circuit breaker. In exactly the same manner as just described, each of the other circuit breakers will control the transmission of two supervisory codes, the first group of impulses of which are always the same and the second group being diflerent by reason of the position of the armature equivalent to armature 430 of the particular circuit breaker.

By employing the first five contacts and the last ten contacts of the code sender, fifty is connected to an ammetershunt in the main comprises aJKelvin balance am neter A which bus 440 of thesubstatiom The Kelvin 'balance operates in a well-known manner to will be noted that, whi e the relay 450 was in a deenergized condition, the circuit of the relay 451 was closed and this relay-became energized to establish a locking circuit for itself and to prepare certain other circuits as will appear. The relay 452, u on being energized, closes the starting circuit for the finder switch F-l in the same manner as the relay 420 or 421, as before described. These 0 erations cause the functioning of the rider switch F-l, the code sending switch CD1 and the connector H1 in the usual manner. By these operations, certain rela s in the relay group RG-4 and roup R --5 are energized and locked in at position. It will be assumed that thee relays are the relays 710 and 706, When the group selecting relay 710 of the first selecting group RG-5 is energized, acircuit is momentarily closed by the operation of the relay 601 of the connec tor H-l for the relay 738 in a manner before described. The relay 738, upon operating, opens up the locking circuit of that one of the relays, such as the relays 735, 736 and 737, which may be energized, thus causing this relay to retract its armatures. This operation opens the circuit of a certain load indicating lamp which may be lit.

Now at the end of the selecting operation, when the wipers of the connector H1 are in engagement with their twenty-fifth set of bank contacts, a circuit is closed in the usual manner for energizing the relay 735. This relay operates to establish a locking circuit for itself at armature 739 and, at the armature 740, closes a circuit for the load indicating lamp 750. This lamp will now con- .tinue to burn, indicating to the dispatcher that there is a certain load on the substation until a change in voltage occurs, whereupon it is extinguished by a code being sent back and another lamp lighted. The operation of the alarm relay 770, of course, calls the attention of the load dispatcher to the change in voltage in the same manner as has been before described. The dispatcher then operates the key K1' to stop the operation of the alarm.

Whenever any change in voltage occurs across the busses 440 and 441 at the substation the contact maker 433 on the Kelvin balance A is operated to open the circuit of the relay 450 and to close a circuit for a relay similar to it. It will thus be seen that there is a group of rela s, such as relays 450, 451 and 452, provided or each contact of the contactor 433 in the Kelvin balance. These relays operate in a slightly different manner from the relays, such as relays 420, 421 and 422, which are associated with the other apparatus units and contactors in the substation.

It will now be assumed that the contactor 445 at the substation is open and that the load dispatcher desires toclose it. In order to accomplish this result, the dispatcher operates the double-throw key K in a direction to momentarily close the springs shown on the right.

The operation of the key K closes a circuit which extends from ground by way of the spring 100 and its working contact through the winding of'the relay 106, the conductor 183, the front contact and the armature 713, and thence to the'battery. The relay 106 is energized over this circuit and operates to establish a locking circuit for itself at the armature 173 over a path extending from ground by way of the armature 17 3 and its front contact, the sprin 17 6 and its resting contactthrough the win ing of the relay 106, the conductor 183, and thence to battery by way of the front contact and the armature 713. The operation of the armature 172 of the relay 106 closes a circuit from the monitor lamp 174. This lamp remains lighted through the sending operation, even after the key K restores to normal, in order to inform the dispatcher that the desired code is beinv sent. Another result of'the energization of th'e relay 106 is that at the armature 103 a circuit is completed which extends from ground by way of the armature 103 and its working contact, through the winding of the stepplng magnet 109 of the finder switch F,

the armature 132 and its back contact, and thence to the battery byway of the back contact and the armature 120. As the stepping magnet 109 interrupts its own circuit, it operthrough the winding of the relay 108 yw'ay of the common conductor 134, which iscommon to all the keys in the group, the front contact and the armature 101, the bank contact 130, the wiper 126 and the coil of the relay 113 to battery. The relay 113 is ener-' gized over the circuit,-and, upon operating,

, terval afterwards.

t us stopping the operation of the finder switch, and closes a circuit for the relay 111 extending from battery by way of the armature 120 and its front contact, through the coil of the relay 111, the bank contact with which the wiper 160 is in engagement, and the said wiper to ground, at armature 121 .closes a circuit WhlCh extends from ground by way ofv the armature 121 and its front contact, through the coil of the slow release relay 143, and thence to battery by way of the armature 152 andits back contact. The relay 111, upon being energized, closes a circuit for the slow-release relay 110 at its armature 117.

The armature 117 of the relay 111 is constructed in a manner similar to the relay 527 of the code sendin switch CD-l and,consequently, when the relay becomes deenergized. the armature 117 vibrates for an in- The relay 110, upon operating, at the armature 115 closes a circuit for the relay 140 and, at the armature 116, establishes a circuit which extends from round by way of the armature 121 and its ront contact, through the coil of the repeating relay 144, the front cont-act and the armature 116 and to battery by way of the armature 152 and its back contact. The repeating relay 144, u on operating, at its armature 154, closes a ridge across the conductors 180 and 181 extending to the substation whereby the line relay 200 of the connector H is energized.

The line rela 200, upon operating, closes a circuit for t 'e slow-release relay 202 in parallel with the ste ping magnet 207. The stepping magnet 20 is energized to place its associated pawl in osition to actuate the switch shaft. The s ow-release rela 202, upon being energized, closes a circuit or the slow-release relay 203. The latter relay operates to energize the slow-release relay 206. The operations of these relays have the same functions as described in connection with the connector H-1.

Returning now to the operation of the code sending switch CD, the relay 140, upon operating, at its armature 148 closes a circult for the slow-release relay 141. The relay 141, upon attracting its armature, establishes a circuit for the slow-release relay 142. The latter relay, upon bein energized, closes a circuit which extends rom ground by way of the armature 155 and its back contact, the front contact and the armature 151, the front contact and the armature 153, through the coil of the magnet 146, by way of the wiper 162 and its associated ank contact, and thence to battery by way of the armature 148 and its front contact. The steppin magnet 146 is energized over this circuit an operates to place its associated pawl in position to actuate the switch shaft and also to open the circuit of the relays 144 and 143 at the armature 152. The deener ization of the relay 144 opens the circuitof t e line relay 200 of the connector H at the substation. The slowrelease relay 143, u on being deenergized, opens the circuit of t e stepping ma net 146, which is also deenergized, to re-esta lish the circuit of the relays 143 and 144, and to advance the switch wipers '160 to 163, inclusive, into engagement with their first set of bank contacts. The stepping of the code sending switch CD continues under the control of the slow-release relay 143 until the wipers of the switch are brought into enga ement with the contact set which includes t e-contact 165. "When this occurs, a circuit is com leted which extends from round by way oft 'e armature 104 of the re? the wiper 125, the bank contact 129, the bank contact 165, the wiper 161, and through the coil of the relay 145 to the battery.

The relay 145 is energized over this circuit and, upon operating, it opens the circuit of the stepping magnet 146 at the armature 155, at the front contact of this armature pre ares another circuit for the magnet and at t e armature 156 opens the circuit of the slow-release relay 141. The rotation of the switch, of course, ceases.

The slow-release relay 141, u on being deenergized, opens the circuit 0 the slow-release relay 142. After a short interval, the slow-release relay 142 retracts its armature and closes a circuit which extends from ground by way of the armature 155 and its ront contact, the back contact and the armature 151, the front contact and the armature 153, through the coil of the stepping magnet 146, the wiper 162 and the bank contact with which the said wiper is in engagement, and thence to battery by way of the front contact and the armature 148. The

stepping magnet 146 operates to attract its armature, thereby placing the pawl in actuating position and/ opening the circuit of the slow-release relay 143 and also the circuit of the relay 144.

In accordance with the first operation of the code sending switch CD, a series of interruptions' is produced in the circuit of the line relay 200 of the connector H. This relay is deenergized a plurality of times in response thereto. As a result of the retractions of the armature 209, the circuits of the slowrelease relay 202 and the magnet 207 are opened. The deenergizations of the magnet 207 serve to advance the switch wipers 225 to 228, inclusive, in engagement with the bank contact set which corresponds to the number of impulses sent over the trunk line and,

consequently, the position of the wipers 160 to 163, inclusive, ofthe code sending switch CD. At the first off-normal step of the switch, the relay 201 is energized over a circuit from ground through relay 201, switch ay 106 and its front contact,

and wiper 327, battery and ground and grounds the conductor 260. It will be assumed that the bank contact set to which the Wipers 225 to 228, inclusive, are stepped includes the bank contact 230.

During the interval that the slow-release relays 141 and 142 in the code sendlng switch are being deenergized, the slow-release relay 203 of the connector H, which has been ma 1ntained energized by the continued operatlon of the armature 209 imdeenergized. As a result of this operation, a circuit is completed which extends from round by way of the armature 211 and its ront contact, armature 221 and its front contact, wiper 225, bank contact 230, conductor 262, through the coil of the relay 306, conductor 271, and to battery, by wa of the armature 215 and its back contact. he relay 306 is energized over this circuit and operates to close a locking circuit for itself at the armature 322 to ground on the conductor 260.

Adverting to the operation of the code sending switch CD, the deenergization of the slow-release relay 142 closes a circuit for the magnet 146 which is energized to place its associated pawl in actuating position and to open the circuit of the slow-release relay 143 and also the circuit of the repeating relay 144. The slow-release relay 143, upon being deenergized, opens the circuit of the stepping magnet 146, which is deenergized. The retraction of the armatures of the magnet 146 advances the switch wipers another step and also closes the circuit of the interrupting relay 143 and the repeating relay 144. By the movement of the switch'wipers, the circuit of the relay 145 is opened and this relay retracts its armatures to open the circuit of the ma et 146 and to close the circuit of the slow-re ease relay 141. The ener 'zation of the relay 141 closes the circuit 0 the relay 142.

The operation of the relay 142 again starts the operation of the stepping magnet 146. The magnet 146 is now intermittently operated to advance the wipers 160 to 163, inclusive, into engagement with the bank contact set, which includes the contact 166. A circuit is now closed which extends from ground by way of the armature 104 of the relay 106 andv its front contact, armature 119 of the rela 108 and its front contact, wiper 124, ban contact 128, bank contact 166, wiper 161, and through the winding of the rela 145 to battery. The relay 145 is ener 'ze to momentarily stop the operation of t e switch wipers in the same manner as before described.

The repeating relay 144 operates to interrupt the circuit at the line relay 200 of the connector H in the same manner a before. The line relay 200 operates to control the operation of the stepping magnet 207 in advancing the wipers 225 to 228, inclusive, into engagement with the proper bank contact set,

which, it will be assumed, includes the bank contact 231. At the termination of this series of impulses, the slow-release relay .204, which has been energized while the switch wipers were being rotated past the twelfth, thirteenth and fourteenth set of bank contacts and has been maintained energized by the operation of the line relay 200, is deenergized and a circuit is closed which extends from ground by way of the front contact and the armature 211, the armature 21 and its front contact, the wiper 225, the bank contact 231 the conductor 268, through the winding of the relay 303, the conductor 270, and the armature 219 and its front contact to battery. The relay 303 is operated over this circuit and attracts its armatures to establish a locking circuit for itself at the armature 350 and to prepare a circuit at the armature 319 for the relay 404 in the substation.

Going back now to the operation of the code sendin switch CD, the slow-release relays 141 an 142 operate, as before, and the magnet 146 is operated after an interval to advance the wipers 160 to 163, inclusive, into engagement with the twenty-fifth set of bank contacts.

When the wipers 160 to 163, inclusive, are brought into engagement with the twent fifth set of bank contacts, the circuit of t e stepping magnet 146 is opened at contact 167 and its operation ceases temporarily. A circuit is also completed which extends from ground by way of the wiper 160 and its associated twenty-fifth bank contact, and throu h the winding of the relay 112 to battery. e relay 112 is energized to prepare a circuit for the stepping magnet 109, the function of which will be described subsequently. Another result of the rotation of the wipers to the twenty-fifth position is that the circuit of the relay 111 is o ened at the twent -fifth contact of the switc of wiper 1.60. he relay 111 is immediately deenergized,. to cause its armature 117 to vibrate. The relay 110 is thus maintained ener ized for an interval after the relay 111 is deenergized. In the same manner as before described, the wipers of the connector H are brought into engagelay 110 in the dispatchers oifice is maintained energized, the slow-release relay 205 in the connector H at the substation is deenergized and a circuit is completed which extends from battery by way of the back contact and the armature 220, the conductor-269, the conductor 372, through the winding of the relay 404, the conductor 371, the armature 319 and its front contact, and thence to ground, by way of the front contact and the armature 323. The relay 404 is operated over this circuit and closes a circuit at its armature 416 for the contactor 445 and, at the armature 415, closes a circuit for the relay 421 for a purpose to be described later. The circuit for relay 421 is completed over a circuit from ound through relay 421, armature 415 and its front contact, back contact and armature 429, battery to ground.

s As the contactor 445 has been assumed be open, its energization serves to close 1t. In the same manner as before described the dispatcher receives a supervisory signal back in order to notify him that the desired operation has taken place.

There is a slig t difference in the operation in this instance, however, inasmuch as the 717 is lighted by the eenergization of the relay 700. The relay 700, upon retracting the armature 713, causes the re ay 106 to deenerg The deenergization of the relay 106 opens the operating circuits of the finder switch F and the code sendin switch CD insuring that the operating co e will not be sent to the substation again.

The contact 415 on the relay 404 at the substation is provided so that, m case the contactor 445 should already be in a closedposition, an answer-back signal will be given to the dispatcher in order to check the super- This is accomplished as folvisory signals. lows I With the contactor 445 already closed, an energizing circuit is completed for the relay 422 over the pallet contacts 446. The ener-. gization of relay 422 completes an energlzing circuit for the relay 421 over the armature 429 and its front contact. Now, when the relay 404 is energized in the manner above described, an energizing circuit is completed for the relay 420 from ground through the winding of relay 420, front contact and armature 415, front contact and armature 429 andbattery to ground. The relay 420 is energized to complete a circuit for the. armature 429 and armature 424 for the stepping magnet 504 in the manner already described and the finder switch now functions to first find the apparatus unit and then transmit a code individual to its condition.

The locking relay 106 also provides means whereby, if, for some reason or other, the code is not transmitted properly, the operation will occur repeatedly until the corresponding contactor or apparatus unit is operated in the substation. By the con'oint action of the checking contact 415 o the relay 404 at the substation and the locking relay 106 associated with the key K, provision is madeso that, if the answer-back code is not transmitted properly, it will be sent back repeatedly until the proper indication is given to the load dispatcher.

Returning now to the operation of the code sending switch CD it will be remembered that the circuit of the slow-release relay 110 is finally opened by the cessation of the vibra '109 is operated over p the wipers 123 to 125 inclusive.

tion of'the armature 111. The relay 110 upon being deener ed, opens the circuit of the slow-release re ay 140 at the armature 115, at the armature 116 opens the circuit of the relay 144, and at the armature 114 closes a circuit which extends from the battery, by we of the front contact of the armature 118 an the said armature, the armature 114 and its back contact, the back contact and the armature 132, through the winding of the stepping magnet 109, the front contact and the armature 103 to grl'ound. The magnet t 's circuit to advance The slow r'e'lease relay 140, upon being s owenergized, opens the circuitof the release relay 141 and closes a circuit which extends from 'gr'ound'by wayof the armature 147 and its back contact, through the winding of the ste ping magnet 146, the armature 149 and its ack contact, the bank contact with which the wiper 163 is in engagement and the said wiper, and thence to battery, by way of the armature 152 and its back contact. The magnet 146 operates to restore the wipers 160 to 163, inclusive, to normal position. By this operation, the circuit'of the relay 112 is o ened and this relay is deenergized to open t e circuit of the stepping magnet 109 of the finder switch F whereby the rotation of the wipers of the finder switches ceases. The slow-release relay 141, upon retracting its armature, opens the circuit of the slow-release relay 142, which is also deenergized. In the above manner, the connection is released responsive to transmitting of the sending operation.

The reason that the finder switch F is given I a number of steps at the end of the code transmitting operation is to allow the calls to be evenl d stributed over the group of keys. To exp ain more fully, assuming that another relay, such as 106, is'operated in addition to the said rela by the momentary operation. of another ey K, were it not for the provision mentioned, the code corresponding to the operated relay would be transmitted indefinitely until the proper answer-back; signal were recorded on the lamps, and there would be no actuating code sent out for the other relay, which was operated. By means of the circuit arrangement shown, this difliculty is obviated and one transmitting operatlon cannot indefinitely closed. If no other relay, such as or 106,

is operated, the finder switch F may a in rotate the wipers 123 to 126, inclusive, into engagement with the bank contacts 127 to 130, inclusive. 1

In case the dispatcher momentarily oper- 

